The aim of this project is to breed and investigate a new animal model for atheroscherosis. We have a small number of pigs which have moderate elevations in cholesterol and triglyceride but die of atherosclerosis on a normal chow diet by 3 years of age. The specific aims are: 1. To breed the animals and create large colony which will permit in vivo experiments to be performed. In addition this will provide a valuable resource for other investigators who wish to use this new model. 2. To elucidate the molecular basis for the mutation responsible for the predisposition to atherosclerosis. The specific hypothesis which is being tested is that there is a mutation in the structure of one of the apoproteins of one or more plasma lipoproteins or that there is a mutation in an enzyme which modifies one or more of the apoproteins.